单项选择题
Which of the following is not a maritime perils?（）.
A.Stranding or grounding B.Striking upon rocks or shoals C.Collision between ships D.Fire
单项选择题 Which is the proper method of determining whether a portable CO2 fire extinguisher needs recharging?（）
单项选择题 Which condition is necessary for a substance to burn?（）
单项选择题 When retrieving the survival craft，the winch operator should stop the winch and check（）.
